They will approach a protected ecosystem, which is thriving with fish like that of the galapagos islands, for example. They will hang out right at the limit of the maritime nautical border with the native country.
Then they will shut down naval GPS transponders (disabling of AIS - Automatic Identification System) and during the night, all at the same time, cross into the country's maritime space and quickly get out before its caught by the local patrols. [1][2]
This happens a lot with smaller countries which cannot fight back.
There are other techniques that haven't been yet discussed, like, altering vessel measurements (Changing draft and length to obscure activity, e.g., during transshipment or EEZ entry) , and meeting with refrigerated cargo ships to transfer catch which is likely illegal.
These are the only ways they can sustain a 44% of fishing worldwide. If they did this in their home turf, their waters would be empty of life
[1] https://www.opendemocracy.net/en/democraciaabierta/pesca-ile...
[2] https://usa.oceana.org/press-releases/oceana-analysis-shows-...